Project Type: social behaviour

Social status significantly affects
Darwinian fitness by altering health, life history, and physiological
trade-offs. Because social status is usually stable throughout life and is a behaviourally transmitted trait, social
inequalities persist within and across generations. Even so, the molecular
mechanisms underlying these social effects are poorly understood. We
hypothesize that DNA-methylation is a main epigenetic pathway through which an
individual’s social environment regulates gene expression and hence
physiological responses and life-history trade-offs. We predict that
methylation patterns in individuals experiencing social stability will promote
status-specific trade-offs. We further predict that when the social environment
results in status changes as when high (low) born offspring are reared by
a low (high) status surrogate mother, plasticity in methylation patterns should
match the gene regulatory pathways, life-history trade-offs and fitness to the
new social conditions. We test our hypothesis using long-term data obtained
from spotted hyenas in the Serengeti National Park. To assess the impact of
status-specific methylation patterns on health, we will measure faecal
immunoglobulin, cytokine levels and eukaryome diversity, and will control for
the possible confounding effect of gut microbiomes. By linking for the first
time in a wild social mammal changes in social status to DNA-methylation,
fitness and health, this project will shed light on gene pathways underpinning
social inequalities, their plasticity, health consequences and potential
implications for humans.